Gain insights into relational databases and SQL. Learn about creating, managing, and editing tables using MySQL. Explore complex queries, indexes, and join functions for efficient data handling.

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Relational databases store data in a row-based table structure. Structured Query Language (SQL) is a core language used to retrieve data from the relational database. One of its most widely used extensions, MySQL, also gives you the power to edit, create, and manage the queried data.

In this course, you’ll be introduced to the basics of relational database management with SQL. You’ll use MySQL to create a table, edit the data, and even change the structure. You’ll also create indexes to quickly access data for faster performance on common queries. Additionally, you’ll explore more complex queries to extract useful data with aggregate functions, grouping, ordering, and creating limits and filters in output tables. Finally, you’ll learn how to combine data from different tables with join functions.

By the end of this course, you’ll be able to create, manage, edit, and merge relational databases with confidence. MySQL will prepare you for data projects large and small.

Getting Started with SQL and Relational Databases

# How does data modeling work?
Let’s take a look at the following diagram. This is something we’ll need to understand very well.


The above diagram explains the following:

* An RDBM server can manage multiple databases at the same time.
* Each database contains one or more tables. A database with no tables is useless.

* Each table contains one or more columns. A table without columns is useless too.
* There are relationships between the tables of a database. That is why we call this system a relational database management system.


Let’s see an example of the above.

In the above example, we have one RDBMS managing the following two databases:

* `customer_management_db`
* `reporting_db`

Each database has its tables:

* The `customer_management_db` database has the following tables:
  * `customers`
  * `products`
  * `orders`
  * `order_lines`
* The `reporting_db` database has the following tables:
  * `sales_per_day`
  * `costs_per_day`

And each table has its columns, like we see below:

For example:
* The `customer` table has the following columns:
  * `name`
  * `contact_address`
  * `contact_phone`
* The `products` table has the following columns:

  * `code`
  * `price`

Since each database has its own tables, that means that we can use the same name in two different tables as long as those tables belong to different databases.


Learn about the basics of data modeling.


Getting Started

Manage MySQL Server

Basic SQL Commands

Add Columns and Indexes

Count and Sort Records

Foreign Keys

Joins, Left Joins And Subqueries

Conclusion

Data Modeling

How does data modeling work?